I got caught out by one when I first started punting as the EE girls had good feed back. It left me sceptical of parties on AW as I lost a far chunk on a deposit. Now follow the rule if someone asks for a deposit they can go take a running jump.
I wouldnt pay a deposit even if i knew a SP was genuine, quite simply punting for me is a pay on the day pastime. I could die, have an accident or someone i know might, i might not feel like punting on the day or even if genuine the SP could have to cancel. Would i see my deposit back if i asked for it, and even if i did i would have to go to pick it up as i wouldnt give them my real details to be able to refund me into a bank account or to my home.